Problem Statement

Following the recent PR that clarified ambient mode update strategy limitations, we need to document the potential approach for enabling RevisionBased updates with ambient mode in the future. Currently, our   documentation states that only InPlace strategy is supported due to ZTunnel's singleton architecture, but we should provide guidance on what would be required to enable RevisionBased support.

Current Documentation State

• Documentation clarifies only InPlace is supported for ambient mode
• Technical reasoning provided (ZTunnel singleton architecture)
• RevisionBased procedures removed from waypoint documentation
• No guidance on future RevisionBased enablement approach

Proposed Documentation Work

• Document technical constraints preventing RevisionBased + ambient
• Outline architectural changes needed for future RevisionBased support
• Create design document for RevisionBased ambient approach
• Document testing strategy for future implementation
• Update user-facing docs with "future considerations" section

Acceptance Criteria

• Architecture document explains ZTunnel singleton limitations
• Design document outlines multi-version ZTunnel approach
• Documentation includes future RevisionBased considerations
• Testing approach documented for validation
• User guidance provided for current limitations and future plans

Related Work

• Recent documentation PR clarifying ambient mode update limitations
• Upstream Istio ambient mode architecture considerations